This is one of the all-time 5 greatest, alongside its successor Memento Mori 2, Requiem, Alien Vendetta, and Hell Revealed. It was also one of the first megawads to focus on co/op play. Yes, it is aged, but the overall quality of the maps is still amazingly high. I regard some of these maps as among the very best ever made, period. Almost nothing is as classic in the long history of Doom as Memento Mori. If you haven't yet, play it through (perhaps with a friend!) and be pleasantly surprised. --5/5